1. Field of the Invention
The invention relates in general to an electronic apparatus, and more particularly to a head mounted display (HMD) apparatus.
2. Description of the Related Art
Along with the advance in technology, people assimilate more and more information every day. Commonly seen electronic apparatuses such as multimedia play apparatus, network communication apparatus and computer apparatus are equipped with a cathode ray tube (CRT) or a liquid crystal display (LCD) for displaying images. However, the pixels and size of a displayed image depend on the size and efficiency of the display, and a conventional CRT or LCD cannot meet the requirements of large size and convenient portability at the same time. To resolve the above problem, an optical see-through head mounted display (HMD) apparatus is provided. The head mounted display apparatus has a CRT or LCD disposed in front of each eye. The head mounted display apparatus projects the images outputted by respective CRT or LCD onto the user's retinas through beam splitters and creates a 3D effect by using the parallax between the user's two eyes.
In a conventional optical see-through HMD apparatus, a beam splitter is disposed in front of each eye and cannot be adjusted. Moreover, in order to achieve a certain viewing angle, the beam splitter of a conventional HMD apparatus must have a certain thickness because the beam splitter is a cube polarizing beam splitter (cube PBS). Thus, it becomes even more difficult for a conventional optical see-through HMD apparatus to reduce its volume.